Quantitatively calculate the magnetoresistance and Hall effect of real materials from first principles

Institute of Physics, Chinese Academy of Sciences (IOP CAS)

This talk will introduce a method that combines first-principles calculations with semiclassical Boltzmann transport theory to quantitatively calculate the magnetoresistance (MR) and Hall effect in real materials including non-magnetic metals, semimetals, semiconductors, and magnetic materials. It discusses the unsaturated MR and anisotropic MR effects in both topologically trivial and topological materials, revealing the crucial roles of carrier compensation, open orbit mechanisms, and Fermi surface topology. The study shows that theoretical predictions are highly consistent with low-temperature experimental results in typical metals, semimetals, and Weyl semimetals, and also discovers that Kohler's rule applies to Hall resistivity, clarifying the proportional relationships and intrinsic laws between ordinary Hall effect and anomalous Hall effect. For the anomalous resistance peaks and Hall resistivity sign reversals in narrow-gap semiconductors, we propose a unified explanation based on multicarrier dynamics and Fermi surface geometry. The introduced new method successfully explains the complex magnetoresistance and Hall effect behaviors in magnetic materials, aligning closely with experiments, highlighting the decisive role of Fermi surface shape and average scattering time on transport properties. We will also introduce a new interpretation of the peculiar behavior of the rho-T curves under magnetic fields. Our talk provides a new theoretical framework for understanding magnetotransport phenomena and opens new avenues for material classification and characteristic characterization.